JP4635479B2 - Audio output device and audio output method - Google Patents

Description

  The present invention relates to an audio output device and an audio output method.

  Conventionally, an audio that has a switch that can be turned on / off and outputs an audio signal given from a medium (for example, a CD (Compact Disc), an MD (Mini Disc), etc.) at an output level corresponding to the on / off operation of the switch. An output device is known (for example, Patent Document 1). In the audio output device, the output level corresponding to the switch-on operation is higher than the output level corresponding to the switch-off operation.

Therefore, the user of the sound output device can hear the sound signal output from the sound output device more accurately than when the switch is turned off by turning on the switch.
JP-A-9-179585

  However, the conventional technique has the following problems. That is, the audio signal given from the low quality media contains more noise than the audio signal given from the high quality media. Here, the low quality media is media having an S / N ratio of a predetermined value or less, and the high quality media is media having an S / N ratio larger than the predetermined value. Examples of the low quality media include a radio receiver and a television receiver. Examples of high quality media include CD and MD. The predetermined value is set in advance.

  Therefore, when the user of the audio output device listens to the audio signal given from the high-quality media, the user can hear the audio signal without feeling troublesome even if the switch is turned on. However, when the user of the audio output device listens to an audio signal given from low-quality media, the user can feel annoying noise if the switch is turned on. Therefore, the conventional audio output device has a problem that the user of the audio output device can feel annoying noise when the switch is turned on.

  As a means for solving such a problem, it is conceivable that the user of the audio output device performs an on / off operation of the switch according to the quality of the media. However, it is troublesome for the user of the audio output device to perform the on / off operation of the switch according to the quality of the media, and it takes time to memorize how to operate the switch according to the quality of the media. .

  The present invention has been made in order to solve such a conventional problem. The main object of the present invention is that the user of the audio output device is more sensitive than the conventional device even if the switch is kept on. It is an object to provide an audio output device and an audio output method that do not feel annoying.

In order to achieve the above object, in the invention described in the claims of the present application, the audio output device outputs an audio signal given from the medium at an output level corresponding to the operation of the switch and the quality of the medium. Here, the maximum and minimum values of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to the high quality media in the on state of the gain adjustment range switching by the switch on operation are the gains by the switch off operation. When the switching of the adjustment range is off, the maximum and minimum values of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to the high-quality media are larger and the gain adjustment range is switched by operating the switch. It is larger than the maximum value and the minimum value of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to the low quality media in the on state and the off state, respectively.

  In the invention described in the claims of the present application, the following effects can be mainly obtained. That is, according to the present invention, when the on operation is performed, the audio output device can output the audio signal given from the high quality media at the same output level as the conventional one, while giving from the low quality media. The received audio signal can be output at a lower output level than before. Therefore, even if the user of the audio output device continues the on-operation, it does not feel more troublesome than before. Also, the audio output device can obtain the same effect as the conventional one when outputting a high quality audio signal.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, based on FIG. 1, the function of the audio | voice output apparatus 1 which concerns on one embodiment of this invention is demonstrated roughly. Here, FIG. 1 is a block diagram showing a configuration of the audio output device 1.

  The audio output device 1 is mounted on a vehicle (not shown), and includes a switch 107, a microcomputer 108, a display unit 109, a DSP (Digital signal processor) 110, a power amplifier unit 111, and speakers 116 to 119. The audio output device 1 includes a CD 101, an MD 102, a radio receiver 103, and a television receiver 105 as various media. Therefore, the CD 101 and the MD 102 are high quality media, and the radio receiver 103 and the television receiver 105 are low quality media. The power amplifier unit 111 includes power amplifiers 112 to 115.

  The CD 101 and MD 102 store various audio signals. The radio receiver 103 includes an antenna 104 and receives a radio signal using the antenna 104. When receiving a request signal from the DSP 110, the radio receiver 103 extracts an audio signal from the received radio signal and outputs it to the DSP 110. The television receiver 105 includes an antenna 106 and receives a television signal using the antenna 106. When receiving a request signal from the DSP 110, the television receiver 105 extracts an audio signal from the received television signal and outputs the audio signal to the DSP 110.

  The switch 107 can perform an output level adjustment operation, a media selection operation, a balance adjustment operation of the speakers 116 to 119, and a volume adjustment operation of the speakers 116 to 119 in addition to an on / off operation. Output to the microcomputer 108. Here, the output level adjustment operation is an operation for designating a peak value (specifically, a maximum value or a minimum value) of the output level in the low sound region and the high sound region. Here, the low frequency range is a frequency range from 20 (Hz) to 250 (Hz), and the high frequency range is a frequency range from 3000 (Hz) to 20 (kHz).

  The microcomputer 108 outputs a control signal corresponding to the operation signal to the display unit 109 and the DSP 110.

  The display unit 109 displays the content of the operation performed by the switch 107 on the screen based on the control signal.

  The DSP 110 performs the following processing based on the control signal. That is, the DSP 110 acquires an audio signal from the CD 101 when a media selection operation for selecting the CD 101 is performed, and receives an audio signal from the MD 102 when a media selection operation for selecting the MD 102 is performed. get. In addition, when a media selection operation for selecting the radio receiver 103 is performed, the DSP 110 outputs a request signal to the radio receiver 103, and in response thereto, an audio signal given from the radio receiver 103 is output. get. In addition, when a media selection operation for selecting the television receiver 105 is performed, the DSP 110 outputs a request signal to the television receiver 105, and in response thereto, an audio signal provided from the television receiver 105 is output. get. In the following description, an audio signal given from the CD 101 and the MD 102 is referred to as a high quality audio signal, and an audio signal given from the radio receiver 103 and the television receiver 105 is referred to as a low quality audio signal.

  Then, the DSP 110 adjusts the output level of the bass region and the treble region of the acquired audio signal to an output level corresponding to the on / off operation, the output level adjustment operation, and the media selection operation. When the DSP 110 is turned on, the DSP 110 adjusts the output level in the 250 (Hz) region of the acquired audio signal to 0 (dB) (flat value) or less. Further, the DSP 110 sets the amplification factors of the power amplifiers 112 to 115 to amplification factors corresponding to the balance adjustment operation and the volume adjustment operation.

  And DSP110 outputs the audio | voice signal which adjusted the output level to power amplifier 112-115.

  The power amplifier 112 amplifies the audio signal given from the DSP 110 with the amplification factor set by the DSP 110 and outputs the amplified signal to the speaker 116. The power amplifier 113 amplifies the audio signal given from the DSP 110 with the amplification factor set by the DSP 110 and outputs the amplified signal to the speaker 117. The power amplifier 114 amplifies the audio signal given from the DSP 110 with the amplification factor set by the DSP 110 and outputs the amplified signal to the speaker 118. The power amplifier 115 amplifies the audio signal given from the DSP 110 with the amplification factor set by the DSP 110 and outputs the amplified signal to the speaker 119.

  Speakers 116 to 119 output audio signals provided from power amplifiers 112 to 115. The speaker 116 is attached to the right front part of the vehicle interior, and the speaker 117 is attached to the left front part of the vehicle interior. Moreover, the speaker 118 is attached to the right rear part of the vehicle interior. The speaker 119 is attached to the left rear part in the vehicle interior.

  Next, the range of peak values that can be specified by the output level adjustment operation will be described with reference to FIG. FIG. 2 is an explanatory diagram showing graphs A1 to A8 and a1 to a8. Here, graphs A1 to A8 show the range of peak values that can be specified by the output level adjustment operation. Graphs a1 to a8 show initial values of output levels. In FIG. 2, “BAS” means “low range”, and “TRE” means “high range”. The graphs a1 to a8 will be described later.

  When the user of the audio output device 1 performs an off operation and performs a media selection operation for selecting the CD 101 or the MD 102, as shown in the graphs A1 to A2, the output level of the bass region and Any peak value in the high sound region can be specified within a range of −10 (dB) to +10 (dB).

  In addition, when the user of the audio output device 1 performs an on operation and performs a media selection operation for selecting the CD 101 or the MD 102, the output of the bass region is output as shown in the graphs A3 to A4. Both the level and the peak value of the treble region can be specified within the range of 0 (dB) to +20 (dB).

  When the user of the audio output device 1 performs an off operation and performs a media selection operation for selecting the radio receiver 103 or the television receiver 105, the graphs A5 to A6 are shown. In addition, both the output level of the bass region and the peak value of the treble region can be specified within the range of −14 (dB) to +6 (dB).

  Further, when the user of the audio output device 1 performs an on operation and performs a media selection operation for selecting the radio receiver 103 or the television receiver 105, the graphs A7 to A8 are shown. In addition, both the output level of the low sound region and the peak value of the high sound region can be specified within the range of −10 (dB) to +10 (dB).

  Next, the output level adjusted by the DSP 110 will be described with reference to FIGS. Here, FIGS. 3 and 4 are graphs B, B0, C, and C0 showing the relationship between the output level and the frequency of the audio signal on a plane in which the horizontal axis represents the frequency of the audio signal and the vertical axis represents the output level. It is explanatory drawing drawn.

  As shown in FIG. 3, when the DSP 110 performs an off operation and performs a media selection operation for selecting the CD 101 or the MD 102, as shown in the graph B, the DSP 110 displays the bass region and the treble region. The output level is adjusted so that the peak value matches the peak value specified by the output level adjustment operation. Here, when the output level adjustment operation is not performed, the DSP 110 adjusts the output level so that the peak values of the bass region and the treble region become 0 (db) as shown in the graph B0 (FIG. (See graphs a1 and a2 shown in FIG. 2). Also, the DSP 110 adjusts the output level of the middle sound region (the region between the low sound region and the high sound region) to a value (or 0 (dB)) closer to 0 (dB) than the low sound region and the high sound region.

  As illustrated in FIG. 4, when the DSP 110 performs an on operation and performs a media selection operation for selecting the CD 101 or the MD 102, as illustrated in the graph C, the DSP 110 displays the bass region and the treble region. The output level is adjusted so that the peak value matches the peak value specified by the output level adjustment operation. Here, when the output level adjustment operation is not performed, the DSP 110 adjusts the output level so that the peak value of the bass region and the treble region becomes 10 (db) as shown in the graph C0 (FIG. 2 (see graphs a3 to a4 shown in FIG. 2). Further, the DSP 110 adjusts the output level of the middle sound region to a value (or 0 (dB)) closer to 0 (dB) than the low sound region and the high sound region, and sets the output level at 250 (Hz) to 0 (dB). ) Adjust to the following values. As a result, the maximum values of the bass and treble regions (specifically, the maximum value of the peak value) are 10 (dB) larger than the maximum values of the bass and treble regions in the graph B. Similarly, the minimum value (specifically, the minimum value of the peak value) of the bass region and the treble region is 10 (dB) larger than the minimum value of the bass region and the treble region in the graph B.

  When the DSP 110 is turned off and a media selection operation for selecting the radio receiver 103 or the television receiver 105 is performed, the peak values of the bass region and the treble region are output level adjusted. Adjust the output level to match the peak value specified by the operation. Here, when the output level adjustment operation is not performed, the DSP 110 adjusts the output level so that the peak values of the bass region and the treble region are −4 (db) (the graphs a <b> 5 to 5 illustrated in FIG. 2). a6). Further, the DSP 110 adjusts the output level of the middle sound region to a value (or 0 (dB)) closer to 0 (dB) than the low sound region and the high sound region. As a result, the maximum values of the bass region and the treble region are 4 (dB) smaller than the maximum values of the bass region and the treble region in the graph B. Similarly, the minimum values of the bass region and the treble region are 4 (dB) smaller than the minimum values of the bass region and the treble region in the graph B.

  Further, when the DSP 110 is turned on and a media selection operation for selecting the radio receiver 103 or the television receiver 105 is performed, the peak values of the bass region and the treble region are output level adjustments. Adjust the output level to match the peak value specified by the operation. Here, when the output level adjustment operation is not performed, the DSP 110 adjusts the output level so that the peak values of the bass region and the treble region become 0 (db) (graphs a7 to a8 shown in FIG. 2). reference). Further, the DSP 110 adjusts the output level of the middle sound region to a value (or 0 (dB)) closer to 0 (dB) than the low sound region and the high sound region. The DSP 110 adjusts the output level at 250 (Hz) to a value of 0 (dB) or less. Thereby, the maximum values of the bass region and the treble region are 10 (dB) smaller than the maximum values of the bass region and the treble region in the graph C. Similarly, the maximum values of the bass region and the treble region are 10 (dB) smaller than the minimum values of the bass region and the treble region in the graph C.

  Therefore, when the output level adjustment operation is not performed, the output level has the following characteristics. In other words, the output level corresponding to the on operation and the high quality media is larger than the output level corresponding to the off operation and the high quality media, and larger than the output level corresponding to the low quality media. Further, the output level corresponding to the off operation and the high quality media is larger than the output level corresponding to the off operation and the low quality media. Further, the output level corresponding to the on operation and the low quality media is larger than the output level corresponding to the off operation and the low quality media. In addition, the difference between the output level corresponding to the ON operation and the high quality media and the output level corresponding to the OFF operation and the high quality media (that is, 10 (dB)) is equal to the output level corresponding to the ON operation and the low quality media. Greater than the difference between the operation and the output level corresponding to the low quality media (ie 4 (dB)).

  The reason why the output level of the middle sound area is adjusted as described above is that the audio output device 1 adjusts the output level of the middle sound area as described above so that these output levels are the same. This is because a clearer audio signal can be output than in the case of the above.

  Further, the reason why the output level at 250 (Hz) is adjusted as described above is that the sound signal at 250 (Hz) is heard more densely than the sound signal in the other frequency domain, so the sound output device The reason is that by adjusting as described above, it is possible to reduce the feeling of the volume of the audio signal compared to the case where the adjustment is not performed.

  Next, a procedure of processing by the audio output device 1 will be described. When the user of the audio output device 1 turns on the audio output device 1 and operates the switch 107, the switch 107 outputs an operation signal related to the result of the operation to the microcomputer 108.

  Next, the microcomputer 108 outputs a control signal corresponding to the operation signal to the display unit 109 and the DSP 110. Next, the display unit 109 displays the content of the operation performed by the switch 107 on the screen based on the control signal.

  Next, the DSP 110 performs the following processing based on the control signal. That is, the DSP 110 acquires an audio signal from the CD 101 when a media selection operation for selecting the CD 101 is performed, and receives an audio signal from the MD 102 when a media selection operation for selecting the MD 102 is performed. get. In addition, when a media selection operation for selecting the radio receiver 103 is performed, the DSP 110 outputs a request signal to the radio receiver 103, and in response thereto, an audio signal given from the radio receiver 103 is output. get. In addition, when a media selection operation for selecting the television receiver 105 is performed, the DSP 110 outputs a request signal to the television receiver 105, and in response thereto, an audio signal provided from the television receiver 105 is output. get.

  Next, the DSP 110 adjusts the output level of the bass and treble regions of the acquired audio signal to an output level corresponding to the on / off operation, the output level adjustment operation, and the media selection operation. Further, when the on-operation is performed, the DSP 110 adjusts the output level in the 250 (Hz) region of the acquired audio signal to 0 (dB) or less. Further, the DSP 110 sets the amplification factors of the power amplifiers 112 to 115 to amplification factors corresponding to the balance adjustment operation and the volume adjustment operation.

  Next, the DSP 110 outputs the audio signal whose output level is adjusted to the power amplifiers 112 to 115. Next, the power amplifier 112 amplifies the audio signal given from the DSP 110 with the amplification factor set by the DSP 110 and outputs the amplified signal to the speaker 116. On the other hand, the power amplifier 113 amplifies the audio signal given from the DSP 110 with the amplification factor set by the DSP 110 and outputs the amplified signal to the speaker 117. On the other hand, the power amplifier 114 amplifies the audio signal given from the DSP 110 with the amplification factor set by the DSP 110 and outputs the amplified signal to the speaker 118. On the other hand, the power amplifier 115 amplifies the audio signal given from the DSP 110 with the amplification factor set by the DSP 110 and outputs the amplified signal to the speaker 119.

  Next, the speakers 116 to 119 output audio signals given from the power amplifiers 112 to 115.

  As described above, in the present embodiment, the audio output device 1 outputs an audio signal given from the media at an output level corresponding to the operation of the switch 107 and the quality of the media. Here, the output level corresponding to the on operation and the high quality media is larger than the output level corresponding to the off operation and the high quality media, and larger than the output level corresponding to the low quality media.

  Therefore, when the ON operation is performed, the audio output device 1 can output a high quality audio signal at the same output level as the conventional one, while outputting a low quality audio signal at an output level lower than the conventional one. I can do it. Therefore, even if the user of the audio output device 1 continues the on operation, the user does not feel more troublesome than before. Further, the audio output device 1 can obtain the same effect as the conventional one when outputting a high quality audio signal.

  Further, since the output level corresponding to the off operation and the high quality media is larger than the output level corresponding to the off operation and the low quality media, the audio output device 1 is the same as the conventional case when the off operation is performed. While a high quality audio signal can be output at a lower output level, a lower quality audio signal can be output at a lower output level than conventional. Therefore, even if the user of the audio output device 1 continues the off operation, the user does not feel more troublesome than before. Further, the audio output device 1 can obtain the same effect as the conventional one when outputting a high quality audio signal.

  Further, the output level corresponding to the on operation and the low quality media is larger than the output level corresponding to the off operation and the low quality media. Therefore, the output level corresponding to the on operation is higher than the output level corresponding to the off operation regardless of the quality of the media. Thereby, the user of the audio output device 1 can feel the change of the audio signal due to the on / off operation regardless of the quality of the media.

  As a technique for preventing the user of the audio output device 1 from feeling more troublesome than in the past, the audio output device 1 automatically changes according to the quality of the media (specifically, depending on the operation of the switch 107). A technique for adjusting the output level is also conceivable. However, this technique has the following problems. That is, when the user of the audio output device 1 wants to adjust the output level, it is necessary to know how the audio output device 1 is adjusting the output level. However, in this technique, since the audio output device 1 automatically adjusts the output level, the user of the audio output device 1 does not know how the audio output device 1 adjusts the output level. It's not easy. Therefore, in this technology, the user of the audio output device 1 may be confused by the operation of the audio output device 1.

  However, in the present embodiment, the output level corresponding to the on operation is greater than the output level corresponding to the off operation regardless of the quality of the media. Can intuitively understand how to adjust the output level. Therefore, the user of the audio output device 1 can adjust the output level without being confused by the operation of the audio output device 1.

  Also, the difference between the output level corresponding to the ON operation and high quality media and the output level corresponding to the OFF operation and high quality media corresponds to the output level corresponding to the ON operation and low quality media and the off operation and low quality media. It is larger than the difference with the output level. Therefore, the user of the audio output device 1 can grasp the change of the audio signal due to the ON operation more accurately when listening to the high quality audio signal than when listening to the low quality audio signal.

  In addition, since the output level corresponding to the off operation and the high quality media is a flat value, the audio output device 1 outputs the high quality audio signal at the same output level as the conventional one even when the off operation is continued. Can be output.

  In addition to adjusting the output level as described above, the audio output device 1 adjusts the output level according to the output level adjustment operation, so that the user of the audio output device 1 can adjust the output level according to his / her preference. Can be adjusted.

  In this embodiment, the CD 101, MD 102, radio receiver 103, and television receiver 105 are used as media, but other media such as a cassette tape may be used. The output level values indicated by the graphs A1 to A8, a1 to a8, B, B0, C, and C0 are examples, and the audio output device 1 may adjust the output level to other values. Further, the DSP 110 may generate a so-called reverberant sound as an audio signal and output it to the power amplifier unit 111. The audio output device 1 may not be mounted on the vehicle. In addition, it goes without saying that the present embodiment may be changed without departing from the spirit of the present invention.

In this embodiment, the switch 107 corresponds to the “switch” described in the claims, and the DSP 110 corresponds to the “output means” described in the claims.

It is a block diagram which shows the structure of the audio | voice output apparatus which concerns on one embodiment of this invention. It is explanatory drawing which shows the value of the output level which can be designated by output level adjustment operation. It is explanatory drawing which shows the output level adjusted by DSP. It is explanatory drawing which shows the output level adjusted by DSP.

Explanation of symbols

1 ... Audio output device 101 ... CD
102 ... MD
DESCRIPTION OF SYMBOLS 103 ... Radio receiver 104 ... Antenna 105 ... Television receiver 106 ... Antenna 107 ... Switch 108 ... Microcomputer 109 ... Display part 110 ... DSP
111 ... Power amplifier unit 112-115 ... Power amplifier 116-119 ... Speaker

Claims (7)

A switch capable of an on / off operation for switching on / off switching of a gain adjustment range for a low sound region and a high sound region of an audio signal given from a medium;
An output means for outputting the low tone region and the high tone region of the audio signal at an output level obtained by performing gain adjustment processing in an on / off state of switching of a gain adjustment range by an on / off operation of the switch and a gain adjustment range corresponding to the quality of the media; With
The maximum value and the minimum value of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to high-quality media in the on state of switching of the gain adjustment range by the switch on operation are the gains by the switch off operation. A gain adjustment range that is greater than a maximum value and a minimum value of a gain adjustment range of a low tone region and a high tone region of the audio signal corresponding to the high-quality media in an off state of switching of the adjustment range, and that is operated by operating the switch. An audio output device characterized by being larger than a maximum value and a minimum value of a gain adjustment range of a low sound region and a high sound region of the sound signal corresponding to a low-quality medium in an on state and an off state of switching, respectively. The audio output device according to claim 1,
The maximum value and the minimum value of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to the high-quality media in the off state of the switching of the gain adjustment range by the switch off operation are determined by the switch off operation. An audio output device characterized by being larger than a maximum value and a minimum value of a gain adjustment range of a low tone region and a high tone region of the audio signal corresponding to the low-quality media in the off state of switching of the gain adjustment range. The audio output device according to claim 1 or 2,
The maximum value and the minimum value of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to the low-quality media in the on state of the switching of the gain adjustment range by the switch on operation are determined by the switch off operation. An audio output device, wherein the gain adjustment range is larger than a maximum value and a minimum value of a gain adjustment range of a low tone region and a high tone region of the audio signal corresponding to the low quality media in an off state of switching of the gain adjustment range. In the audio output device according to any one of claims 1 to 3,
The gain adjustment range of the audio signal corresponding to the high-quality media in the on state of the gain adjustment range switching by the switch ON operation and the gain adjustment range switching by the switch OFF operation are turned off. The difference between the maximum value and the minimum value of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to the high-quality media in the state is that the gain adjustment range is switched on by turning on the switch. In the state, the audio signal corresponding to the low quality media in the off state of switching the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to the low quality medium and the gain adjustment range by turning off the switch Between the maximum and minimum values of the gain adjustment range of the bass and treble regions of An audio output device and greater than. In the audio output device according to any one of claims 1 to 4,
The gain of the center value of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to the high-quality media in the off state of switching of the gain adjustment range by the switch-off operation is 0 dB. Audio output device. In the audio output device according to any one of claims 1 to 4,
The switch is capable of adjusting the output level of the low sound region and high sound region of the audio signal,
The output means adjusts the output level of a low sound region and a high sound region of the sound signal according to the adjustment operation. Gain adjustment processing was performed within the gain adjustment range corresponding to the quality of the media and the operation of the switch that can be turned on and off to switch on and off the switching of the gain adjustment range for the bass and treble regions of the audio signal given from the media An output step of outputting the audio signal at an output level;
The maximum value and the minimum value of the gain adjustment range of the low tone region and the high tone region of the audio signal corresponding to high-quality media in the on state of switching of the gain adjustment range by the switch on operation are the gains by the switch off operation. in the off state of the switching of the adjustment range, greater respectively than the maximum value and the minimum value of the gain adjustment range of the bass region and the treble region of the audio signal corresponding to the high-quality media,且one, gain adjustment by the operation of the switch An audio output method characterized by being larger than a maximum value and a minimum value of a gain adjustment range of a low tone region and a high tone region of the audio signal corresponding to low quality media in an on state and an off state of range switching, respectively.

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